Interleukin-1 receptor-associated kinases (IRAKs) are important mediators of signaling processes, such as toll-like receptors (TLR) and interleukin-1 receptor (IL-1R) signaling processes. IRAKs have been implicated in modulating signaling networks that control inflammation, apoptosis, and cellular differentiation. Four IRAK genes have been identified in the human genome (IRAK1, IRAK2, IRAK3 and IRAK4), and studies have revealed distinct, non-redundant biological roles. IRAK1 and IRAK4 have been shown to exhibit kinase activity.